Bluish-gray vat dye.



PAUL THOMASGHEWSKI AND HEINRICH RAEDEZR, F VOHWINKEL, AND WALTER MIEGAND PAUL FISCHER, 0E ELBERFELD, GERMANY, ASSIGNORS T0 FARIBENFABRIKENVOBM. FRIEDR. BAYER & (70., OF ELBERFELD, GERMANY, A CORPORATION OFGERMANY.

BLU'ISH-GRAY VAT DYE.

Patented Sept. 27, 1910.-

No Drawing. Original application filed February 12, 1910, Serial No.543,493. Divided and this application filed April 21, 1910. Serial No.556,653.

To all whom it may concern:

Be it known that we, PAUL THOMASCHEWSKI and HEINRICH RAEDER, residing atVohwinthe German Empire, have invented new and useful Improvements inBluish-Gray Vat Dyes, of which the following is a specification.

Our present invention relates to the manufacture and production of a newvat dye of the anthracene series.

The process for its reparation consists in condensing 1-benzoylm1no-4-chloroanthraquinone with l-benzoylamino-4-aminoanthra uinone. Thenew product is after being ied and pulverized and crystallized fromnitrobenzene a dark powder having a metallic luster, soluble inconcentrated sulfuric acid with a green color, turning brown after sometime. It yields on treatment with hydrosulfite and caustic soda lye avat suitable for dyeing cotton fast bluish-gray shades.

In carrying out the new process practically wecan proceed as fol ows,the parts being by weight: A mixture of 12 parts of1-benzoylamino-4-ch1oroanthraquinone, 11 parts ofl-benzoylaminoi-aminoanthraquinone, 2 parts of (11101 6 parts ofanhydrous sodium acetate and 200 parts of nitrobenzene is heated toboiling for about 3 hours. The resulting product is precipitated fromthe melt with alcohol. After cooling'the dye is filtered off, washedwith water and alcohol.

We claim The herein described new vat dyestufi' of the anthracene serieswhich can be obtained from 1-benzoylaminol-chloroanthraquinone and'l-benzoylaminol-aminoanthraquinone, which dyestufl' is, after beingdried and pulverized, a dark powder having a metallic luster, which issoluble in concentrated sulfuric acid with a green color soon turningbrown; yielding a vat with hydrosulfite and caustic soda lye, which vatdyes cotton bluishgray shades, substantially as described.

In testimony whereof we have hereunto set our hands in the presence oftwo subscribing witnesses.

PAUL THOMASGHEWSKI. HEINRICH RAEDEB. WALTER MIEG.

PAUL FISCHER.

Witnesses Orro Komc, WALTER Vonnncur.

